1. Field of Invention
This invention generally relates to video technology, particularly to managing multiple video sources.
2. Related Art
For many years, television was relatively simple. A consumer purchased a television, and received broadcast video signals over an antenna. The number of available channels was limited to those channels for which a sufficient signal was
With the advent of cable and satellite television, video cassette recorders (VCRs), digital video disc (DVD) systems, digital video recorder (DVR) systems, and set-top boxes (Internet protocol (IP) or traditional), consumers have access to a large number of channels and a wide variety of personal video recording devices (PVRs).
DVR systems are relatively new to the consumer market, but are being widely embraced by consumers looking for easier and more flexible ways to time-shift their viewing. While VCRs require a user to use external media to record programming, DVR systems include high capacity internal storage (e.g., one or more high capacity hard drives). Additionally, DVR systems may provide a number of advantages not found with available VCR systems, like periodic channel and schedule updating, user-defined recording criteria, and the like.
Another emerging technology is the IP set-top box. An IP set-top box is a dedicated computing device that acts as an interface between a television and a network (such as an IP-based network). IP set-top boxes are able to provide many of the advantages of DVR systems, and may also receive video data over IP connections (rather than traditional video connections such as cable and satellite connections). Like DVR systems, IP set-top boxes provide easier and more flexible time-shifted viewing.
As device manufacturers expand the capabilities of their products, many are beginning to provide users with the ability to record and/or view multiple programs at the same time. For example, some available DVR systems employ multiple tuners to allow recording/viewing of multiple programs at the same time. For IP set-top boxes, the number of simultaneous incoming video sources is no longer limited directly by the number of physical interfaces on the device. In current systems the primary tuner alone is active when a single channel is being viewed or recorded. If the secondary tuner was active (due to, e.g., recording), the tuner may remain locked onto a channel and continue to buffer data for that channel. Thus, if the user returns to channel x after viewing channel y, the system needs to re-lock on channel x. Therefore, the user may experience delay due to the reacquisition and locking of the video signal and/or data buffering.